It all started on Saturday, when Kris Jenner teased some big announcement from Kendall on Twitter.

"I'm so proud of my darling @KendallJenner for being so brave and vulnerable," Kris wrote.

"Seeing you share her most raw story in order to make a positive impact for so many people and help foster a positive dialogue is a testament to the incredible woman you've become."

She told everyone to "Make sure to watch @KendallJenner's Twitter on Sunday night to find out what I'm talking about and be prepared to be moved."

After that, it was time to go to town on some hashtags: Kris added ones like "be the change," "share your story," "change the conversation," "proud mom," "finally a solution," "authenticity," "my daughter inspires me," and "get ready."

On top of all of that, she also shared a video of Kendall saying "It's OK, and I can help you, and I experienced it and I'm very normal."

So this sounded like a very, very big deal, right?

Kris made it sound like Kendall had been through something truly horrific, or that she was going to open up about something really serious.

Lots of people thought it would have something to do with her mental health, since she's been open about her issues with anxiety.